Only use methods available in .NET 3.5 (and higher).

src/Renci.SshNet.Tests/Classes/Common/ExtensionsTest_Concat.cs

@@ -157,7 +157,8 @@ namespace Renci.SshNet.Tests.Classes.Common
 
             Console.WriteLine(stopWatch.ElapsedMilliseconds);
 
-            stopWatch.Restart();
+            stopWatch.Reset();
+            stopWatch.Start();
 
             for (var i = 0; i < runs; i++)
             {

src/Renci.SshNet.Tests/Classes/Common/ExtensionsTest_IsEqualTo_ByteArray.cs

@@ -168,7 +168,8 @@ namespace Renci.SshNet.Tests.Classes.Common
 
             Console.WriteLine(stopWatch.ElapsedMilliseconds);
 
-            stopWatch.Restart();
+            stopWatch.Reset();
+            stopWatch.Start();
 
             for (var i = 0; i < runs; i++)
             {

src/Renci.SshNet.Tests/Classes/Common/ExtensionsTest_Take_Count.cs

@@ -164,7 +164,8 @@ namespace Renci.SshNet.Tests.Classes.Common
 
             Console.WriteLine(stopWatch.ElapsedMilliseconds);
 
-            stopWatch.Restart();
+            stopWatch.Reset();
+            stopWatch.Start();
 
             for (var i = 0; i < runs; i++)
             {